Front calipers great, but rear ones rust.
 

Is there a solution for this? Too bad Audi didn't use the same ones on the rear!

https://cimg9.ibsrv.net/gimg/www.aud...885f7a5dc7.jpg

https://cimg4.ibsrv.net/gimg/www.aud...7318fa74ee.jpg

When my Q5 TDI was delivered there were tiny rust spots on rear calipers. Applied a rust treatment (Ospho) to rear calipers as well as the painted portion of front and rear rotors with an artist's brush then painted with an aluminum paint. I keep these areas coated with a protectant (Rejex). They look pretty but a lot of effort for cosmetic touch only a fanatic would notice.

I painted mine, and repaint every spring. They look fabulous. It's really easy once the wheels are off for the seasonal tire swap. I've done it 4-5 times and still have over 1/2 can of paint left.

Go here:

https://www.audiworld.com/forums/q5-...aning-2843941/

FWIW the calipers are aluminum and the rust stains are coming from the pad backing plate.

For aluminum, they sure are heavy.